1. Field of the Invention
The present invention relates to a matching circuit of an amplifier which amplifies a microwave signal or millimeter wave signal such as encountered in mobile communications, and relates to a low distortion transistor circuit using a matching circuit.
2. Description of Related Art
With the appearance of high-capacity digital mobile communications systems, there is an increased demand for low-distortion, high-output power amplifiers. Along with this, in order to lengthen the possible total connect time for mobile telephone systems, there is a demand for high-output power amplifiers which operates with high efficiency. In the past, the feedback method and pre-distortion method have been investigated for use in achieving distortion compensation in high-output power amplifiers. Another method of distortion compensation is, for example, as indicated at the 1996 Electronics Society Conference C-94 of the Institute of Electronics, Information and Communication Engineers of Japan, that of using series diode linearization, or that of using a combination of a silicon bipolar transistor and a preamplifier or applying a source inductor.
In the above-noted distortion compensation circuits, however, because the attenuator circuit is provided before the power amplifier to be distortion-compensated for the purpose of adjusting level, the circuit configuration is both complex and large, thus making it difficult to achieve a compact circuit.
In view of the above-described drawbacks in the prior art, an object of the present invention is to provide circuit configuration technology that enables the implementation of a compact, low-distortion high-output power amplifier using a simple fabrication method, while also providing high-efficiency operation.